This is a proposal for the continued development and application of a new transmission electron diffraction method for accurately measuring the electron density distribution of cations in various crystalline materials. Electron beam techniques will enable the PIs to study the structure of micro-crystals and "real" materials. Specifically, the PIs intend to: * determine the charge state of Cu in various oxides including oxide superconductors * study the nature of bonding and crystal properties of MgO * test theoretical calculations such as structure factors and the role of ionicity in structural phase transitions * further develop the electron diffraction technique The results of this research will contribute to the understanding of the crystal structure of a number of technologically important semiconductor and ceramic materials.
